Looks like a Game Boy and allows you to play 8bit games. It’s the Arduboy, a game system the size of a credit card that features a brilliant OLED display, 6 soft-touch tactile buttons and a 2 channel speaker being powered by a 8+ hour rechargeable battery. Yes all that in just a 5 mm thick device.
Arduboy is also an open platform for people to create and share games, and it comes with the Arduboy Arcade which includes completely free games built on the Arduino software.
The Arduboy will begin shipping this October and it’s $39 for early birds. For more info check out the video below and the official project page on Kickstarter.